In the antenna art it is often highly desirable, especially when dealing with projectiles, missiles, and aircraft, to be able to construct antenna means which exhibit a selectable radiation polarization while having a low profile for aerodynamic reasons. Various types of antenna devices are known in the prior art which exhibit a desirable aerodynamic profile. However, since most conventional antennas are inherently either linearly or circularly polarized, it is necessary to have at least two antennas and associated power dividers, phase shifters, and rf switches to provide complete polarization coverage. It would be highly desirable to construct a single antenna element which could provide complete polarization coverage without the necessity of using power dividers, phase shifters, etc.
It is therefore an object of this invention to provide a microstrip antenna element which is capable of providing selectable radiation polarization.
It is also an object of this invention to provide an antenna element which will provide polarization coverage without the necessity of multiple antennas or associated complex circuitry. It is a further object of the invention to provide an antenna element which may be selectively polarized in any one of several polarization senses by simple electronic switching.
It is yet another object of the invention to provide such an antenna having a low profile and desirable aerodynamic qualities.